feat: 增强模板条件渲染表达式支持

使用 simpleeval 库替换原有的简单正则匹配，支持复杂的条件表达式评估。新增 ConditionEvaluator 类处理条件逻辑，支持比较运算、逻辑运算、成员测试、数学计算和内置函数，同时保持向后兼容性。

tests/unit/test_template.py

@@ -145,15 +145,36 @@ class TestEvaluateCondition:
         assert result is False
 
     def test_evaluate_condition_with_missing_variable(self, sample_template):
-        """测试缺失变量条件为假"""
+        """测试缺失变量会抛出错误"""
         template = Template("title-slide", templates_dir=sample_template)
-        result = template.evaluate_condition("{subtitle != ''}", {})
-        assert result is False
+        with pytest.raises(YAMLError, match="条件表达式中的变量未定义"):
+            template.evaluate_condition("{subtitle != ''}", {})
 
-    def test_evaluate_condition_unrecognized_format_returns_true(self, sample_template):
-        """测试无法识别的条件格式默认返回 True"""
+    def test_evaluate_condition_complex_logic(self, sample_template):
+        """测试复杂逻辑表达式"""
         template = Template("title-slide", templates_dir=sample_template)
-        result = template.evaluate_condition("some other format", {})
+        result = template.evaluate_condition(
+            "{count > 0 and status == 'active'}",
+            {"count": 5, "status": "active"}
+        )
+        assert result is True
+
+    def test_evaluate_condition_member_test(self, sample_template):
+        """测试成员测试表达式"""
+        template = Template("title-slide", templates_dir=sample_template)
+        result = template.evaluate_condition(
+            "{status in ['draft', 'review']}",
+            {"status": "draft"}
+        )
+        assert result is True
+
+    def test_evaluate_condition_math_operation(self, sample_template):
+        """测试数学运算表达式"""
+        template = Template("title-slide", templates_dir=sample_template)
+        result = template.evaluate_condition(
+            "{(price * discount) > 50}",
+            {"price": 100, "discount": 0.8}
+        )
         assert result is True